1. Field of the Invention
The present invention relates to a hinge suitable for use with an original pressing plate of a copying machine, printing machine or the like to open and close the original pressing plate.
2. Description of the Prior Art
Various types of original pressing plate hinges have ever been proposed. A typical one of them includes a fixing member to be installed to the body of an object provided with an original pressing plate, such as a copying machine or the like, and on which the hinge is to be used, a supporting member to support the original pressing plate, pivotably installed via a hinge pin to the fixing member, a slider housed slidably in the supporting member, a cam member fixed between opposite lateral plates of the fixing member in contact with the slider, and a coil spring provided resiliently between the slider and the free end of the supporting member.
Another typical one of them includes a fixing member to be installed to the body of an object provided with an original pressing plate, such as a copying machine or the like, on which the hinge is to be used, a supporting member to support the original pressing plate, pivotably installed via a hinge pin to the fixing member, a slider housed slidably in the supporting member, a cam member fixed between opposite lateral plates of the fixing member in contact with the slider, a coil spring provided resiliently between the slider and the free end of the supporting member, and a damping member housed in the coil spring to be put into action when a heavy original pressing plate, if applied, is closed to a predetermined angular position, to thereby prevent the original pressing plate from falling abruptly.
In the above-mentioned conventional original pressing plate hinges including the cam member and slider, a lubricant has to be applied to the surface of the cam member fixed between the opposite lateral plates of the fixing member. When the original pressing plate is opened or closed with an original set on a platen glass or contact glass, for copying or printing, the surface of the cam member applied with the lubricant is exposed so that the end of the original placed on the platen glass may possibly touch the lubricant on the cam member if the original is moved out of place, and thus the original is likely to be stained with or spoiled by the lubricant.
Also, in the above-mentioned conventional original pressing plate hinge using the damping member, once the hinge is assembled, the damping member cannot easily be removed or accessed because it is housed in the coil spring also housed in the supporting member.
Further, the supporting member of each of the above conventional original pressing plate hinges is pivotably installed via the hinge pin to the fixing member fixed to the body of the object on which the hinge is to be used. Therefore, if the fixing member has bearing members made of a non-conductive material such as synthetic resin and in which the hinge pin is pivotably supported, no electrical connection can be provided between the object and the original pressing plate provided with an automatic document or original feeder, for example.
Accordingly, it is an object of the present invention to overcome the above-mentioned drawbacks of the prior art by providing an original pressing plate hinge constructed, with no cam member fixed to the fixing member, to avoid that the cam member surface applied with the lubricant would otherwise be exposed towards the original placed on the platen glass as in the conventional original pressing plate hinges.
It is another object of the present invention to provide an original pressing plate hinge using a slider housed in a supporting member and whose cam surface needs not to be lubricated, that is, a so-called lubricant-free original pressing plate hinge.
It is a still another object of the present invention to provide an original pressing plate hinge which attains the above objects and further includes a damping member.
It is a yet another object of the present invention to provide an original pressing plate hinge of which a damping member can freely be removed even after the hinge itself is assembled or after it is installed to the body of an object having an original pressing plate and on which the hinge is to be used.
It is a still yet another object of the present invention to provided an original pressing plate hinge including a fixing member having bearing members made of a non-conductive material and in which a hinge pin is pivotably supported, an electrical connection being assured between the fixing member and supporting member.
The above object can be attained by providing an original pressing plate hinge including:
a fixing member consisting of a base plate, which is to be fixed to the body of an object provided with an original pressing plate and on which the hinge is to be used, opposite lateral plates rising from opposite lateral sides of the base plate;
a supporting member to support the original pressing plate and which consists of a back plate, top plate formed by bending the back plate, opposite lateral plates, and holding plates formed by bending the opposite lateral plates, one end of each of the opposite lateral plates of the supporting member being pivotably installed via a hinge pin to outside of the opposite side plates of the fixing member;
a cam slider having one end thereof formed as a cam-shaped portion and which is slidably held by holding plates of the supporting member and directed towards the fixing member;
a pressure receiving pin supported between the opposite lateral plates of the fixing member in contact with the cam portion of the cam slider;
a coil spring provided resiliently between the cam slider and the top plate of the supporting member;
slots formed on the opposite lateral plates for receiving the holding plates when the supporting member is closed; and
a lifting member for attaching to the original pressing plate which is pivoted to a free end of the supporting member.
Also, the above object can be attained by providing an original pressing plate hinge including:
a fixing member consisting of a base plate, which is to be fixed to the body of an object provided with an original pressing plate and on which the hinge is to be used, and opposite lateral plates rising from opposite lateral sides of the base plate;
a supporting member to support the original pressing plate and which consists of a back plate, top plate formed by bending the back plate, and opposite lateral plates, one end of each of the opposite lateral plates of the supporting member being pivotably installed via a hinge pin to the opposite side plates of the fixing member;
a cam slider having one end thereof formed as a cam-shaped portion and which is slidably housed in the supporting member and directed towards the fixing member;
a pressure receiving pin supported between the opposite lateral plates of the fixing member in contact with the cam portion of the cam slider;
a coil spring provided resiliently between the cam slider and the free end of the supporting member; and
a fluid damping member with a piston rod removably inserted from the top plate of the supporting member into the coil spring, it being activated as a damper with the piston rod caused to abut at the end thereof the cam slider when the supporting member is closed to a predetermined angular position as the original pressing plate is closed.
Also, the above object can be attained by providing an original pressing plate hinge including:
a fixing member consisting of a base plate, which is to be fixed to the body of an object provided with an original pressing plate and on which the hinge is to be used, and opposite lateral plates rising from opposite lateral sides of the base plate;
a supporting member to support the original pressing plate and which consists of a back plate, top plate formed by bending the back plate, and opposite lateral plates, one end of each of the opposite lateral plates of the supporting member being pivotably installed via a hinge pin to the opposite side plates of the fixing member;
a cam slider having one end thereof formed as a cam-shaped portion and which is slidably housed in the supporting member and directed towards the fixing member;
a pressure receiving pin being in contact with the cam portion of the cam slider and supported between the opposite lateral plates of the fixing member;
a coil spring provided resiliently between the cam slider and the free end of the supporting member; and
a fluid damping member having a piston rod and inserted in the coil spring, it being activated as a damper with the piston rod caused to abut at the end thereof the cam slider when the supporting member is closed to a predetermined angular position as the original pressing plate is closed.
Also, the above object can be attained by providing an original pressing plate hinge including:
a fixing member consisting of a base plate, which is to be fixed to the body of an object provided with an original pressing plate and on which the hinge is to be used, and opposite lateral plates rising from opposite lateral sides of the base plate;
a supporting member to support the original pressing plate and which consists of a back plate, top plate formed by bending the back plate, and opposite lateral plates, one end of each of the opposite lateral plates of the supporting member being pivotably installed via a hinge pin to the opposite side plates of the fixing member;
a cam slider having one end thereof formed as a cam-shaped portion and which is slidably housed in the supporting member and directed towards the fixing member;
a pressure receiving pin supported between the opposite lateral plates of the fixing member in contact with the cam portion of the cam slider;
a coil spring provided resiliently between the cam slider and the top plate of the supporting member; and
a fluid damping member with a piston rod and inserted in the coil spring, it being activated as a damper with the piston rod caused to abut at the end thereof the cam slider when the supporting member is closed to a predetermined angular position as the original pressing plate is closed.
Also, the above object can be attained by providing an original pressing plate hinge including:
a fixing member consisting of a base plate, which is to be fixed to the body of an object provided with an original pressing plate and on which the hinge is to be used, and opposite lateral plates rising from opposite lateral sides of the base plate;
a supporting member to support the original pressing plate and which consists of a back plate, top plate formed by bending the back plate, and opposite lateral plates, one end of each of the opposite lateral plates of the supporting member being pivotably installed via a hinge pin to the opposite side plates of the fixing member;
a cam slider having one end thereof formed as a cam-shaped portion and which is slidably housed in the supporting member and directed towards the fixing member;
a pressure receiving pin supported between the opposite lateral plates of the fixing member in contact with the cam portion of the cam slider;
a coil spring provided resiliently between the cam slider and the free end of the supporting member; and
a fluid damping member having a piston rod and inserted between the cam slider in the coil spring and the free end of the supporting member, it being activated as a damper with the piston rod caused to abut at the end thereof the cam slider when the supporting member is closed to a predetermined angular position as the original pressing plate is closed.
Also, the above object can be attained by providing an original pressing plate hinge including:
a fixing member consisting of a base plate, which is to be fixed to the body of an object provided with an original pressing plate and on which the hinge is to be used, and opposite lateral plates rising from opposite lateral sides of the base plate;
a supporting member to support the original pressing plate and which consists of a back plate, top plate formed by bending the back plate, and opposite lateral plates, one end of each of the opposite lateral plates of the supporting member being pivotably installed via a hinge pin to the opposite side plates of the fixing member;
a cam slider having one end thereof formed as a cam-shaped portion and which is slidably housed in the supporting member and directed towards the fixing member;
a pressure receiving pin supported between the opposite lateral plates of the fixing member in contact with the cam portion of the cam slider;
a coil spring provided resiliently between the cam slider and the top plate of the supporting member; and
a fluid damping member with a piston rod, inserted between the cam slider in the coil spring and the top plate of supporting member, it being activated as a damper with the piston rod caused to abut at the end thereof the cam slider when the supporting member is closed to a predetermined angular position as the original pressing plate is closed.
Also, in any one of the above-mentioned original pressing plate hinges, the supporting member may further include a frictional portion which is put in contact with the cam slider when the supporting member is closed to a predetermined angular position as the original pressing plate is closed, thereby controlling the sliding movement of the cam slider.
Also, in any one of the above-mentioned original pressing plate hinges, the fixing member may have bearing members made of a non-conductive material and in which the hinge pin is pivotably supported, a conductive material shaped like a coil spring and being used to electrically connect the supporting member and fixing member to each other.
These objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.